A cold header ductile iron body casting gating system

Abstract

The utility model discloses a kind of nodular cast iron machine body casting pouring systems of cold header, it is related to casting technical field, including inner gate, several inner gates are connected on the body front, and several inner gates are all connected with cross gate, the one end of cross gate and straight runner is connected, the other end of straight runner is connected with gate cup, the direction of the inner gate is perpendicular to body front, the cross gate is rectangular arrangement.This system takes body front as casting bottom surface, uses two packages simultaneously pouring and two groups of bottom injection open pouring system, inner gate is evenly distributed in body front, iron liquid fills type stably, inhibits turbulence and air entrainment, effectively reduce the production of oxidized slag in pouring process and the risk of entering cavity.

Description

Technical Field

[0001] This utility model relates to the field of casting technology, specifically to a casting and gating system for a cold heading machine ductile iron body. Background Technology

[0002] Large cold heading machines, as specialized equipment in the field of metal cold forming, directly affect the forming quality of metal products. However, the heavy ductile iron machine body, a key component of this type of equipment, faces numerous technical bottlenecks during casting due to its ultra-thick and large cross-sectional structure. These bottlenecks include slag inclusions caused by unstable pouring, shrinkage cavities and porosity defects due to solidification shrinkage, poor graphite spheroidization and graphite distortion in the thick cross-section, and existing casting processes that cannot simultaneously meet the requirements for mechanical properties and dimensional accuracy. These issues have become key obstacles restricting the localization and large-scale production of large cold heading machines.

[0003] The heavy-duty cold heading machine body is a thick-section rectangular ductile iron casting made of QT500-7 material. Its gross weight is 50 tons, the weight of the molten iron to be poured is 55 tons, and the maximum wall thickness reaches 400 mm. Therefore, it is urgent to design a casting and gating system for the ductile iron cold heading machine body to solve the casting defects and performance deficiencies of the thick-section ductile iron body and maintain the casting's good performance requirements. Summary of the Invention

[0004] To address the shortcomings and deficiencies of existing technologies, this utility model provides a casting and gating system for ductile iron bodies of cold heading machines. The system uses the front of the body as the casting bottom surface, employs two simultaneous pouring ladles and two sets of bottom-pouring open gating systems, with the inner gates evenly distributed on the front of the body. This ensures stable molten iron filling, suppresses turbulence and air entrapment, effectively reduces the generation of oxide slag during pouring and the risk of it entering the mold cavity, and has the advantages of simple structure and convenient operation.

[0005] It includes an inner gate, several inner gates are connected to the front of the machine body, and several inner gates are connected to the runner. The runner is connected to one end of the sprue through a T-shaped ceramic tube, and the other end of the sprue is connected to the pouring cup.

[0006] As a further implementation, the ingate is made of a ceramic tube, and the direction of the ingate is perpendicular to the front of the machine body.

[0007] As a further implementation, the horizontal runners are arranged in a rectangular pattern.

[0008] As a further implementation, the horizontal runner is supported by several ingates placed on the front of the machine body.

[0009] As a further implementation, the horizontal sprue is made of segmented ceramic tubes, which are connected by wrapping with tape and then reinforced with slender steel bars.

[0010] As a further implementation, the direct gating channel is made of ceramic tubes, and there are two of them, distributed along both sides of the machine body.

[0011] As a further implementation, the cross-sectional area of ​​each gating channel in the gating system is set as ∑F_vertical:∑F_horizontal:∑F_inner = 1.0:(1.5~2.0):(1.5~2.0).

[0012] Compared with the prior art, the beneficial effects of this utility model are: This utility model provides a casting system for ductile iron bodies of cold heading machines. The system uses the front of the body as the casting bottom surface and adopts a two-ladle simultaneous pouring and two sets of bottom-pouring open gating systems. The inner gates are evenly distributed on the front of the body, ensuring smooth molten iron filling, suppressing turbulence and air entrapment, effectively reducing the generation of oxide slag and the risk of it entering the mold cavity during the pouring process. It also has the advantages of simple structure and convenient operation, and can be widely used and promoted in the research and development and production of heavy rectangular castings. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the structure of an embodiment of the present utility model; Figure 2 This is a schematic diagram of the structure of this utility model in its inverted state.

[0014] In the diagram: 1. Front of the machine body; 2. Inner gate; 3. Horizontal runner; 4. Vertical runner; 5. Riser; 6. Sprue cup; 100. Machine body. Detailed Implementation

[0015] The technical solutions of this utility model will be clearly and completely described below with reference to the accompanying drawings. The preferred embodiments described are only examples. All other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0016] like Figure 1 , Figure 2 As shown, the heavy-duty ductile iron body 100 of the cold heading machine is made of QT500-7. Its gross weight is 50T, the weight of the molten iron is 55T, and the maximum wall thickness reaches 400mm.

[0017] The specific implementation method adopts the following technical solution: It includes an inner gate 2, several inner gates 2 are connected to the front side 1 of the machine body, and several inner gates 2 are connected to the horizontal runner 3. The horizontal runner 3 is connected to one end of the straight runner 4 through a three-way ceramic tube, and the other end of the straight runner 4 is connected to the pouring cup 6.

[0018] In this embodiment, the inner gate 2 is made of a Φ50mm ceramic tube, and the direction of the inner gate 2 is perpendicular to the front side 1 of the machine body. There are 28 inner gates 2.

[0019] In this embodiment, the horizontal runner 3 is made of Φ140mm ceramic tube and is arranged in a rectangular shape.

[0020] In this embodiment, the horizontal runner 3 is supported by several ceramic tube inlets 2 placed on the front of the machine body 1. The horizontal runner 3 is made of segmented ceramic tubes, which are connected by wrapping with tape and then reinforced by binding with Φ20mm slender steel bars.

[0021] In this embodiment, the sprue 4 is made of Φ150mm ceramic tube, and there are 2 sprues 4, which are distributed along both sides of the machine body.

[0022] In this embodiment, 15 feeding risers 5 are provided on the top of the body 100, and the cross-sectional area of ​​each gating channel of the gating system is set as ∑F_straight:∑F_horizontal:∑F_inner = 1.0:1.74:1.67.

[0023] The bottom-pouring open gating system is adopted. The molten iron first passes through the pouring cup 6 and then through two ceramic straight sprues 4 from top to bottom into the rectangular horizontal sprue 3. Then, it is evenly distributed from the horizontal sprue into the ceramic inner gate 2, and then vertically enters the mold cavity 100 from the bottom pouring on the front of the machine body 1. This achieves rapid filling of the gating system, stable filling of the mold with molten iron, suppression of turbulence and splashing, and effectively reduces the generation of secondary oxide slag and the risk of it entering the mold cavity.

[0024] It should be noted that in this embodiment, the casting of the machine body 100 is carried out by two ladles simultaneously. After the two ladles have finished casting the body, the speed is reduced and the molten iron is added until the feed riser no longer overflows.

[0025] Based on the theoretical design calculations and MAGMA simulation verification of the large-hole casting outflow, the filling process of the machine body 100 was smooth, without splashing or jetting. As the pouring time progressed, the molten metal showed a uniform and stable upward trend. Throughout the entire filling process, the gating system remained filled with molten iron, effectively preventing gas and slag inclusions from entering and avoiding slag inclusion defects. This verified the rationality of the bottom-pouring process and ensured the quality of the machine body 100.

[0026] In this embodiment, the casting process for the heavy ductile iron body 100 of the large cold heading machine is as follows: After molding and assembly, two 27.5 t molten iron smelted in a medium-frequency electric furnace and inoculated with wire for spheroidization were prepared. After the temperatures of the two molten iron smelted iron smelted in the furnace were measured and found to be within acceptable limits, the castings were poured simultaneously into the full pouring cups. After the main casting was poured, the pouring was slowed down and continued for 5 minutes until no more molten iron overflowed from the feeding riser. The tapping temperature was 1440–1360℃, the pouring temperature was 1310–1330℃, and the pouring time was (210±20) s. The time from the end of the spheroidization treatment to the completion of pouring was ≤20 min. The solidification temperature of the casting body was 1160℃, and complete solidification required 24 hours. The castings were removed from the furnace and the sand was removed after the temperature dropped to ≤300℃. The heat preservation and removal time was 10 days (240 hours).

[0027] It should be noted that the above embodiments are only used to illustrate the technical solution of this utility model, and are not intended to limit it. Those skilled in the art should understand that this utility model can have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A casting and gating system for a ductile iron body of a cold heading machine, characterized in that, It includes an ingate (2), several ingates (2) are connected through to the front (1) of the machine body, and several ingates (2) are connected through to the runner (3). The runner (3) is connected to one end of the sprue (4), and the other end of the sprue (4) is connected through to the pouring cup (6).

2. The casting and gating system for a cold heading machine ductile iron body according to claim 1, characterized in that, The ingate (2) is made of ceramic tube and its direction is perpendicular to the front of the body (1).

3. The casting and gating system for a cold heading machine ductile iron body according to claim 1, characterized in that, The horizontal gating channel (3) is arranged in a rectangular shape.

4. The casting and gating system for a cold heading machine ductile iron body according to claim 1, characterized in that, The horizontal runner (3) is supported by several ingates (2) placed on the front (1) of the machine body.

5. The casting and gating system for a cold heading machine ductile iron body according to claim 1, characterized in that, The horizontal gating system (3) is made of segmented ceramic tubes, which are connected by wrapping with tape and then reinforced by binding with slender steel bars.

6. The casting and gating system for a cold heading machine ductile iron body according to claim 1, characterized in that, The direct casting channel (4) is made of ceramic tubes, there are 2 of them, and they are distributed along both sides of the machine body.

7. The casting and gating system for a cold heading machine ductile iron body according to claim 1, characterized in that: The ratio of the cross-sectional area of ​​each gating runner in the gating system, ∑F_vertical:∑F_horizontal:∑F_internal, is 1.0:(1.5~2.0):(1.5~2.0).

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